Filter repair

The glass in my favorite yellow filter just decided to loosen up; it's as if the adhesive just suddenly failed, and now the glass is loose within the filter ring itself. I'm totally unfamiliar with lens/filter repairs...so what can I use to repair it?

Most filters have a threaded retaining ring. It might be slotted. If you decide to try to tighten it by the slots, use something soft like a toothpick. Otherwise you will certainly scratch it (not serious but unsightly). You might even be able to tighten the whole works by finger. Just grab the filter between thumb and forefinger (with a napkin or something to keep oil off the glass) and twist as if you are tightening a screw. The retaining ring might follow by friction and tighten up as you go.

Some filters have a circular spring retainer that snaps in, some appear to be somehow given a roll crimp to retain the glass, and I believe some have a cement of some sort. Without seeing the situation, I might consider using something relatively benign like white glue in a hypodermic style dispenser to just fill in the gaps, carefully cleaning off any surplus, if it's not a threaded retainer. Years ago I did some work, but not on filters, diluting silicone adhesive with naptha to thin it so it could be applied in very small quantities with a hypodermic needle. At the time, I had access to some fairly exotic industrial adhesives, I'm not 100% sure as to whether it would work with the over the counter home center stuff. I would certainly test first if going that way.

I took a close look and this one seems to have a snap ring of sorts. The ring itself was slightly out of place, and when I carefully pushed at the out-of-place side it snapped back into position...but the glass is still loose. Hmm...perhaps diluted white glue, now?

If I had to fix a loose glass I would use 2component-epoxy glue, spread a thin layer evenly by warming on the metal flange and carefully insert the glass. But this requires care otherwise you make a mess out of the filter. This glue however gives the chance to clean things up in time if necessary. Something that would not work with Methacrylate glue which hardens within seconds.

I took a close look and this one seems to have a snap ring of sorts. The ring itself was slightly out of place, and when I carefully pushed at the out-of-place side it snapped back into position...but the glass is still loose. Hmm...perhaps diluted white glue, now?

Actually, in that case it sounds as though there is solid mechanical retention, so perhaps three or four tiny drops of white glue carefully applied with the end of a toothpick and evenly spaced around the circumference might be enough to keep the glass from rattling around. Using it thicker would reduce the chance of it flowing somewhere not desired. But like AgX, I'm not sure being absolutely tight is that critical, assuming there is no way for it to fall out.

Actually, in that case it sounds as though there is solid mechanical retention, so perhaps three or four tiny drops of white glue carefully applied with the end of a toothpick and evenly spaced around the circumference might be enough to keep the glass from rattling around. Using it thicker would reduce the chance of it flowing somewhere not desired. But like AgX, I'm not sure being absolutely tight is that critical, assuming there is no way for it to fall out.

I'll give the white glue a shot. The looseness isn't a problem until I try to clean the thing...and then it becomes infuriating. I'll post some results when I get them.

How about a shim with a small pieces of aluminum foil or plastic wedged into place with a toothpick. No chance of messy glue and reversible if not satisfactory. Or as Steve says. I've had a filter or two that rattled and never affected the photographs.